One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,6,4,7)(9,10,13,16)(11,15,12,14)(17,18,21,20)(19,22,23,24)(25,26)(27,32)(28,33)(29,34)(30,31)(35,40)(36,37)(38,39)(9,11,13,12)(10,14,16,15)(19,23)(22,24)(26,31)(28,32)(34,39)(36,40)(1,3,5,4)(2,6,8,7)(9,10)(11,15)(12,14)(13,16)(17,19,21,23)(18,22,20,24)(25,27,30,33)(26,32,31,28)(29,37,38,35)(34,36,39,40)(1,2)(3,6)(4,7)(5,8)(17,18,21,20)(19,22,23,24)(25,28,30,32)(26,33,31,27)(29,36,38,40)(34,37,39,35)(1,4,5,3)(2,7,8,6)(9,12,13,11)(10,15,16,14)(17,20,21,18)(19,24,23,22)(25,29,30,38)(26,34,31,39)(27,35,33,37)(28,36,32,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.